The U.S. Environmental Protection Agency was wrong to determine Michigan met federal health and environmental standards for ozone pollution or smog in the Detroit area in 2023, a federal appeals court judge has ruled.

U.S. 6th Circuit Court of Appeals Judge Helene White on Dec. 5 issued a split decision in a case about how environmental regulators measured Detroit air quality in 2022, when wildfire smoke drifted over Detroit and affected the air quality monitor readings for a few days in June.